The essential component parts of the contact with the ground of vehicles are the tires and the suspension devices.
An essential role of the suspension devices is to guide the wheels of the vehicle in such a way that the tires work in the best possible conditions in order to derive the best possible advantage therefrom, whether from the point of view of the dynamic performance of the vehicle or safety or the high mileage capability of the tires.
Suspension devices have thus been proposed in order to guarantee improved control of the camber of the wheels with regard to transverse accelerations, for example by permitting total compensation for the effect of the rolling of the vehicle or even by permitting the inclination of the plane of the wheel towards the inside of the vehicle in corners. In the present application, the expression “for positively controlling the camber of the wheels relative to the ground in case of transverse acceleration” is used when the control has the effect of inclining the wheels towards the inside of the corners. Such suspension devices are described, for example, in documents EP 1070609, WO 2004/058521, EP 0979769 or EP 1752321. These devices may be active, that is to say they may utilize a supply of energy (of electric, hydraulic or other origin) in order to apply the variations in camber or, on the other hand, they may be passive, that is to say they may utilize only the mechanical energy associated with the movement of the vehicle (potential energy or kinetic energy).
These devices have actually permitted a significant improvement in vehicle performance. However, this improvement has not generated sufficient interest in the eyes of the manufacturers for them to compensate for the greater mechanical bulk of these devices. Until now, therefore, this has precluded the adoption of such suspension devices on passenger vehicles.